Turning titanium requires a stable setup, sharp tooling, controlled heat and reliable chip evacuation. A cutting-speed chart is a starting point for a specific combination of alloy, insert grade and chipbreaker; it is not a universal setting for every titanium job.

The reference table summarizes selected external-turning recommendations from Mitsubishi Materials for titanium alloy, with Ti-6Al-4V shown as the example material and MT9015 as the insert grade. It separates the catalog’s finish/light, medium and rough cutting areas and retains the associated speed, feed and depth-of-cut ranges. Treat each range as a starting window to qualify on the actual machine and part.

How to read the ranges

Cutting speed is the surface speed at the tool-workpiece interface, in metres per minute. Feed is the axial advance per spindle revolution, in millimetres per revolution. Depth of cut is the radial engagement for the turning pass. The three values work together: raising feed or depth increases chip load and cutting forces, while speed changes heat generation and tool life. Selecting the upper end of every range at once is not automatically appropriate.

The finish/light, medium and rough labels describe catalog application areas and their chipbreaker choices. A light pass may help control forces and improve the surface, while a roughing pass removes more material but places greater demands on rigidity, insert support and chip control. Use the chipbreaker specified for the intended area. The table combines identical finish/light recommendations only where the catalog lists the same operating window.

Using the chart on a real part

Confirm the exact titanium alloy and condition before choosing a row. Ti-6Al-4V is a common alpha-beta alloy, but its behavior does not make these numbers suitable for commercially pure titanium or every heat-treated grade. Then match the insert grade and chipbreaker, establish the correct tool orientation and verify that the holder, turret, spindle and workholding are rigid enough for the planned engagement.

Begin with a conservative point inside the catalog range and make a controlled trial cut. Check chip shape and evacuation, sound, surface finish, insert wear and workpiece temperature. If the process is unstable, change one variable at a time and consult current tooling guidance rather than compensating blindly with more speed or feed. Coolant delivery, nozzle position and chip flushing matter because titanium can retain heat near the cutting edge.

What this table does not establish

The values are manufacturer recommendations for a stated material example and tooling combination. They do not guarantee tool life, surface integrity, dimensional accuracy or a safe process on a particular machine. Interrupted cuts, slender parts, poor workholding, long tool overhang, thin walls and difficult chip evacuation can require different settings. Use the current Mitsubishi catalog and the insert supplier’s application support when conditions differ.

For production, document the qualified setup, including alloy and condition, insert designation, chipbreaker, coolant method, speed, feed, depth, pass strategy and observed tool life. Requalify after a meaningful change to the machine, material lot, geometry or tooling. This keeps the catalog window useful as a traceable starting point instead of treating it as a one-size-fits-all recipe.

For example, if a trial pass produces long, tangled chips, first confirm the correct chipbreaker and its recommended cutting area. Check whether the tool is reaching the planned depth and whether coolant can clear the chips. A small, recorded feed adjustment may be more useful than an unplanned speed increase. Inspect the insert after the trial and compare the result with the supplier’s wear guidance before committing to a longer run.

These selected values come from the Mitsubishi Materials C010 Turning Tools catalog. Check the current catalog page and insert guidance before applying them to a different grade or cutting condition.